A physically unclonable function (PUF) generator is a physical structure generally within an integrated circuit that provides a number of corresponding outputs (e.g., responses) in response to inputs (e.g., challenges/requests) to the PUF generator. A unique identity of the integrated circuit may be established by such challenge-response pairs provided by the PUF generator. With the establishment of the identity, secure communication can be guaranteed. The PUF generator can also be used for existing authentication purposes to replace the current method of assigning an identity to an electronic device. Since the PUF generator is based on intrinsic properties of a manufacturing process, the PUF has various advantages over conventional authentication approaches that inscribes an identity on a device which may be mimicked and/or reverse engineered more easily.
For quality-control purposes, testing of functionalities of PUF generators after manufacturing is required to determine qualified PUF generators and categorize qualified PUF generators according to their repeatability and uniqueness. There exists a need to develop a method to characterize PUF generators for quality-control purposes at high speed and at low cost in order to identify defective PUF generators, to categorize qualified PUF generators, and to provide insights of the manufacturing processes.